Small chiller won't dry up

[kamersoutdoor]

showed up to look at a small chiller used to cool a laser. Maintenance guy said it wouldn't start so he called the electricians to take a look. Said they found a bad switch so they JUMPED IT OUT He said it ran but still wouldn't cool.
I put my gauges on and read 0 psi. Pressurized and evaporator reservoir overflowed with bubbles.
To make a long story short, I replaced the coil and cannot get rid of the water. I've been purging and pulling a vacuum for going on three days now. (I stop in between jobs to change pump oil and purge). My pump oil continues to be milky white every time. I can get vacuum down to 936 and will hold for an hour before purging again.

Is there anything I can do to hurry this along?
Does my vacuum reading sound right? (It won't raise much, making me think its not boiling off)
Can I throw some heat on the receiver and comp?

Thanks in advance. Will be back at it tomorrow, and hope to see some improvement.

[HVACFITTER562]

For starters, a cold trap before your Vac pump would help pull out the moisture without contaminating your vac pump oil. A heat lamp on the receiver and compressor would help. If it is a water cooled condenser, run some hot water in it, but bring the temperature up slowly +/- 125 .

[Healey Nut]

Run the pump with the ballast open overnight or longer if needed . The oil wont get contaminated and the heavy moisture will be removed , then do your final evacuation with it closed

[kamersoutdoor]

My biggest fear is that they may have ran it enough to mix the oil and water in the comp! Will pulling good enough vac seperate them if this is the case?

BTW
The pump I have on does not have ballast. Didn't want to ruin my JB.
Can you explain the cold trap please? Thanks

[BKS60]

Since your pulling moisture in your pump you can bet there is water in the compressor oil. If its a semi you can drain as much oil out as possible until you get the moisture out and plan on changing oil a few times after startup. If it a hermetic I would plan on replacing the compressor and remove the existing and not install a new one until the moisture problem is corrected.

havcfitter562 has a good point about heatlamps.

The cold pots can be recovery tanks packed with dry ice to collect/freeze the moisture before your vacumm pump or a low temp refrigeration wrap around a tank to do the same. These help with clearing the moisture and protect your pump from damage.

[ga1279]

kamersoutdoor- Yeah that could do it if you have a month or two to wait. Try getting a large nitro bottle or two and run about 30' of coiled copper tubing to one side of the system and let that sucker blast through. The reason for the lengthy copper line is to pick up some heat, lay it on the hot ground or put the tubing roll in a bucket of extremely hot water. (not the connections please) If you do it right you can dehydrate your mini-cooler and blow the oil out of it. Get the model and serial of your compressor and put (some) fresh oil in. (not a whole charge) Then locate your liquid line and install a large liquid line drier (high moisture removal). Apparently the switch your electricians jumped was the low pressure switch and the compressor pulled itself into a vacuum and sucked all that water in the system. Some where down the road when you have some pressure on it with nitrogen or refrigerant you will definitely want to meg out the compressor motor and if it is a little pot and your readings are low, below 4 meg, you may be pi$$ing in the wind and just replace that puppy. Remember NEVER attempt to use a high voltage megger (500 VDC) on a system in a vacuum. You don't need much pressure, just so you're not at that deep vacuum. Good luck and be safe out there.-Geo

[kamersoutdoor]

kamersoutdoor- Yeah that could do it if you have a month or two to wait. Try getting a large nitro bottle or two and run about 30' of coiled copper tubing to one side of the system and let that sucker blast through. The reason for the lengthy copper line is to pick up some heat, lay it on the hot ground or put the tubing roll in a bucket of extremely hot water. (not the connections please) If you do it right you can dehydrate your mini-cooler and blow the oil out of it. Get the model and serial of your compressor and put (some) fresh oil in. (not a whole charge) Then locate your liquid line and install a large liquid line drier (high moisture removal). Apparently the switch your electricians jumped was the low pressure switch and the compressor pulled itself into a vacuum and sucked all that water in the system. Some where down the road when you have some pressure on it with nitrogen or refrigerant you will definitely want to meg out the compressor motor and if it is a little pot and your readings are low, below 4 meg, you may be pi$$ing in the wind and just replace that puppy. Remember NEVER attempt to use a high voltage megger (500 VDC) on a system in a vacuum. You don't need much pressure, just so you're not at that deep vacuum. Good luck and be safe out there.-Geo

Guess I forgot to mention it was LPS. And when spoke with plant manager I explained this (highlighted above) to him. All the time and effort could have been avoided had they called us in the first place.
So you think if done properly the comp can be saved?
I already changed filter when I installed the new coil and planned on changing several times after running.
These companies can be pretty hardheaded, might have to let comp burn-out before approval to replace. Same company that approved replacing two condenser coils and compressor on 20yr old unit for $2,000 less than new unit.
I did explain that comp may be beyond survival.

[kamersoutdoor]

Since your pulling moisture in your pump you can bet there is water in the compressor oil. If its a semi you can drain as much oil out as possible until you get the moisture out and plan on changing oil a few times after startup. If it a hermetic I would plan on replacing the compressor and remove the existing and not install a new one until the moisture problem is corrected.

havcfitter562 has a good point about heatlamps.

The cold pots can be recovery tanks packed with dry ice to collect/freeze the moisture before your vacumm pump or a low temp refrigeration wrap around a tank to do the same. These help with clearing the moisture and protect your pump from damage.

Will try this tomorrow. Thanks!

[Trane_Dude]

Hope it wasen't a 410-A system, otherwise you will NEVER dry it out.

[ga1279]

kamersoutdoor- Yeah, I've had several like that. It's call the bean counters. They can spend until hell freezes over on maint or repair but not nickel on capitol investments, new equipment. One thing, you mentioned plant. Are you in a chemical plant ? If yes see if they have plant nitrogen available then hook it up and let it blow, catch the exhausted nitro through a bucket to catch any oil. I personally would have $hit canned it (Compressor) when I changed out the evaporator. That would give you fresh oil and then pull your TXV and every thing else is wide open for the nitrogen to blow through.-Geo

[jayguy]

My biggest fear is that they may have ran it enough to mix the oil and water in the comp! Will pulling good enough vac seperate them if this is the case?...

no it will not. i have some pictures of an experiment that i performed. 2" of oil on top of 1.5" of water. at 72.3F and 454 microns, the oil just sat there and so did the water. the water did not 'burp' out of the oil until i had warmed up the water to 109F.

do NOT change the compressor oil. REMOVE the compressor oil. evacuate the system, fill with nitrogen, repeat until the system is dry THEN add the new oil and perform your final evacuation.

[Jerry K]

"experiment that i performed. 2" of oil on top of 1.5" of water. at 72.3F and 454 microns, the oil just sat there and so did the water."

The weight of the oil increases the vapor pressure of the water to the point it will not boil at ambiant temperatures. The heat you added(109degf) was enough heat to make the water boil at the vaccum pressure were sitting at (454 microns).

[jayguy]

"experiment that i performed. 2" of oil on top of 1.5" of water. at 72.3F and 454 microns, the oil just sat there and so did the water."

The weight of the oil increases the vapor pressure of the water to the point it will not boil at ambiant temperatures. The heat you added(109degf) was enough heat to make the water boil at the vaccum pressure were sitting at (454 microns).

yup.